Boca Juniors president Daniel Angelici and coach Rodolfo Arruabarrena have slammed the behaviour of spectators at the Copa Libertadores fixture with River Plate on Thursday.

The second leg of the last-16 tie at La Bombonera in Buenos Aires was suspended after the first half, as visiting River players were reportedly attacked with pepper spray as they re-entered the pitch.

After negotiations took place between players, referees, officials - both government and CONMEBOL - and police for over an hour, the Superclasico was eventually called off.

Angelici said those who used pepper spray causing injury to River's Leonardo Ponzio, Leonel Vangioni, Ramiro Funes Mori and Matias Kranevitter were a minority.

"We want to convey the pain, anguish and shame for what happened on Thursday at the stadium," Angelici said in a statement.

"Boca has 110 years of history and always work for these classics are a party, but unfortunately there are always misfits who may commit a criminal act to suspend such an important game.

"It started as a party and we knew we were at a disadvantage but we could reverse the result, but it filled me with anxiety that someone will throw a liquid at a rival."

He added: "I apologised to the president of River because I think that is what is needed. This has to be a party, it's football. It is said to be the loser is the worst, it's a battle and sometimes mistakes are made."

Angelici said stamping out the perpetrators was necessary going forward.

"We must all work to end these episodes," he said.

"There were almost 49,000 people and there were no incidents in 98 per cent of the stadium, but it seems strange that a fan of Boca wants to harm the club, suspend the game and Boca have a penalty."

He revealed Boca will submit a report to CONMEBOL on Saturday, with the governing body expected to reveal a course of action afterwards.

Coach Arruabarrena said he was ashamed of the saga.

"The club has been working for years for families to come to the stadium and these things are moving away," Arruabarrena said.

"Inside the camp there was much confusion, I felt very ashamed, but we want to show solidarity with the players of River.

"I was a player [too] and to see who have suffered aggression around the world is not what we want for our football."

Arruabarrena claimed CONMEBOL officials and referee Dario Herrera wanted to continue the match, but he insisted it should be called off.

"It is true that CONMEBOL and Dario wanted to continue, but the sensible thing was to suspend it for assaulting River players," he said.

"Dario wanted to play, police provided security, but the sensible thing was to be suspended."

River released a statement on Friday, revealing Ponzio, Vangioni, Funes Mori and Kranevitter were all absent from training due to their recovery from corneal abrasions.